summaryrefslogtreecommitdiff
path: root/io_uring/cancel.c
blob: a253e2ad22ebd017f12e369210aafed7965dfc07 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/io_uring.h>

#include <uapi/linux/io_uring.h>

#include "io_uring_types.h"
#include "io_uring.h"
#include "tctx.h"
#include "poll.h"
#include "timeout.h"
#include "cancel.h"

struct io_cancel {
	struct file			*file;
	u64				addr;
	u32				flags;
	s32				fd;
};

#define CANCEL_FLAGS	(IORING_ASYNC_CANCEL_ALL | IORING_ASYNC_CANCEL_FD | \
			 IORING_ASYNC_CANCEL_ANY)

static bool io_cancel_cb(struct io_wq_work *work, void *data)
{
	struct io_kiocb *req = container_of(work, struct io_kiocb, work);
	struct io_cancel_data *cd = data;

	if (req->ctx != cd->ctx)
		return false;
	if (cd->flags & IORING_ASYNC_CANCEL_ANY) {
		;
	} else if (cd->flags & IORING_ASYNC_CANCEL_FD) {
		if (req->file != cd->file)
			return false;
	} else {
		if (req->cqe.user_data != cd->data)
			return false;
	}
	if (cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY)) {
		if (cd->seq == req->work.cancel_seq)
			return false;
		req->work.cancel_seq = cd->seq;
	}
	return true;
}

static int io_async_cancel_one(struct io_uring_task *tctx,
			       struct io_cancel_data *cd)
{
	enum io_wq_cancel cancel_ret;
	int ret = 0;
	bool all;

	if (!tctx || !tctx->io_wq)
		return -ENOENT;

	all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY);
	cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, cd, all);
	switch (cancel_ret) {
	case IO_WQ_CANCEL_OK:
		ret = 0;
		break;
	case IO_WQ_CANCEL_RUNNING:
		ret = -EALREADY;
		break;
	case IO_WQ_CANCEL_NOTFOUND:
		ret = -ENOENT;
		break;
	}

	return ret;
}

int io_try_cancel(struct io_kiocb *req, struct io_cancel_data *cd)
{
	struct io_ring_ctx *ctx = req->ctx;
	int ret;

	WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);

	ret = io_async_cancel_one(req->task->io_uring, cd);
	/*
	 * Fall-through even for -EALREADY, as we may have poll armed
	 * that need unarming.
	 */
	if (!ret)
		return 0;

	ret = io_poll_cancel(ctx, cd);
	if (ret != -ENOENT)
		return ret;

	spin_lock(&ctx->completion_lock);
	if (!(cd->flags & IORING_ASYNC_CANCEL_FD))
		ret = io_timeout_cancel(ctx, cd);
	spin_unlock(&ctx->completion_lock);
	return ret;
}


int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_cancel *cancel = io_kiocb_to_cmd(req);

	if (unlikely(req->flags & REQ_F_BUFFER_SELECT))
		return -EINVAL;
	if (sqe->off || sqe->len || sqe->splice_fd_in)
		return -EINVAL;

	cancel->addr = READ_ONCE(sqe->addr);
	cancel->flags = READ_ONCE(sqe->cancel_flags);
	if (cancel->flags & ~CANCEL_FLAGS)
		return -EINVAL;
	if (cancel->flags & IORING_ASYNC_CANCEL_FD) {
		if (cancel->flags & IORING_ASYNC_CANCEL_ANY)
			return -EINVAL;
		cancel->fd = READ_ONCE(sqe->fd);
	}

	return 0;
}

static int __io_async_cancel(struct io_cancel_data *cd, struct io_kiocb *req,
			     unsigned int issue_flags)
{
	bool all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY);
	struct io_ring_ctx *ctx = cd->ctx;
	struct io_tctx_node *node;
	int ret, nr = 0;

	do {
		ret = io_try_cancel(req, cd);
		if (ret == -ENOENT)
			break;
		if (!all)
			return ret;
		nr++;
	} while (1);

	/* slow path, try all io-wq's */
	io_ring_submit_lock(ctx, issue_flags);
	ret = -ENOENT;
	list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
		struct io_uring_task *tctx = node->task->io_uring;

		ret = io_async_cancel_one(tctx, cd);
		if (ret != -ENOENT) {
			if (!all)
				break;
			nr++;
		}
	}
	io_ring_submit_unlock(ctx, issue_flags);
	return all ? nr : ret;
}

int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_cancel *cancel = io_kiocb_to_cmd(req);
	struct io_cancel_data cd = {
		.ctx	= req->ctx,
		.data	= cancel->addr,
		.flags	= cancel->flags,
		.seq	= atomic_inc_return(&req->ctx->cancel_seq),
	};
	int ret;

	if (cd.flags & IORING_ASYNC_CANCEL_FD) {
		if (req->flags & REQ_F_FIXED_FILE)
			req->file = io_file_get_fixed(req, cancel->fd,
							issue_flags);
		else
			req->file = io_file_get_normal(req, cancel->fd);
		if (!req->file) {
			ret = -EBADF;
			goto done;
		}
		cd.file = req->file;
	}

	ret = __io_async_cancel(&cd, req, issue_flags);
done:
	if (ret < 0)
		req_set_fail(req);
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

void init_hash_table(struct io_hash_bucket *hash_table, unsigned size)
{
	unsigned int i;

	for (i = 0; i < size; i++) {
		spin_lock_init(&hash_table[i].lock);
		INIT_HLIST_HEAD(&hash_table[i].list);
	}
}